…e checking, and associated UI tests

Now users will be able to do:
```
cargo build -Zbuild-std=core -Zbuild-std-features=compiler-builtins-asm
```
and correctly get the assembly implemenations for `memcpy` and friends.

On macOS the test is flaky and sometimes fails,
sometimes succeeds on CI.

For rust-lang#78721 and rust-lang#78722

…ith qualifiers inside an `extern "C"` block

This allows us to:
- Handle precise Places captured by a closure directly in MIR. Handling
captures in MIR is easier since we can rely on/ tweak PlaceBuilder to
generate `mir::Place`s that resemble how we store captures (`hir::Place`).
- Allows us to handle `let _ = x` case when feature `capture_disjoint_fields`
is enabled directly in MIR. This is required to be done in MIR since
patterns are desugared in MIR.

ExprKind::SelfRef was used to express accessing `self` in
the desugared Closure/Generator struct when lowering captures in THIR.

Since we handle captures in MIR now, we don't need `ExprKind::Self`.

Previously, bootstrap.py would attempt to find the LLVM commit from
`src/llvm-project`. However, it assumed it was always being run from the
top-level directory, which isn't always the case.

Before:

```
downloading https://ci-artifacts.rust-lang.org/rustc-builds//rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz

curl: (22) The requested URL returned error: 404
failed to run: curl -# -y 30 -Y 10 --connect-timeout 30 --retry 3 -Sf -o /tmp/tmppyh4w8 https://ci-artifacts.rust-lang.org/rustc-builds//rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
Build completed unsuccessfully in 0:00:02
```

After:

```
downloading https://ci-artifacts.rust-lang.org/rustc-builds/430feb24a46993e5073c1bb1b39da190d83fa2bf/rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
 ###################################################################################################################################################################### 100.0%
extracting /home/joshua/rustc/src/bootstrap/build/cache/llvm-430feb24a46993e5073c1bb1b39da190d83fa2bf-False/rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
```

…cros

…pt level flag to test

Fix rust-lang#58964.

Make bad "rust-call" arguments no longer ICE

The simplest of bad rust-call definitions will no longer cause an ICE. There is a FIXME added for future work, as I wanted to get this easy fix in before trying to either add a hack or mess with the whole obligation system

fixes rust-lang#22565

…stebank

Improve the diagnostic for when an `fn` contains qualifiers inside an `extern` block.

This mitigates rust-lang#78941. As suggested by ```@estebank,``` `span_suggestion` was replaced with `span_suggestion_verbose` for this specific diagnostic.

libary: Forward compiler-builtins "asm"  and "mangled-names" feature

In principle this is a followup of rust-lang#78472. In the previous PR was the support of the test crate missing.

Now users will be able to do:
```
cargo build -Zbuild-std=core -Zbuild-std-features=compiler-builtins-asm
```
and correctly get the assembly implemenations for `memcpy` and friends.

Add //ignore-macos to pretty-std-collections.rs

On macOS the test is flaky and sometimes fails,
sometimes succeeds on CI.

This is no fix for the underlying issue,
but I feel the workaround is worth it as
the issue makes it harder
to get things merged into master.

cc rust-lang#78665

…hievink

Don't special case constant operands when lowering intrinsics

…ark-Simulacrum

Add two regression tests

For rust-lang#78721 and rust-lang#78722

Remove redundant notes in E0275

Fix rust-lang#58964.

…crum

compiletest: Fix a warning in debuginfo tests on windows-gnu

The warning looked like this for me:
```
Warning: C:msys64homewerust./src/etc: No such file or directory.
```
It didn't affect actual testing because we don't currently emit gdb pretty-printer information into executables on windows-gnu.

add optimization fuel checks to some mir passes

Fixes rust-lang#77402

Inserts a bunch of calls to `consider_optimizing`. Note that `consider_optimizing` is the method that actually decrements the fuel count, so the point at which it's called is when the optimization takes place, from a fuel perspective. This means that where we call it has some thought behind it:

1. We probably don't want to decrement the fuel count before other simple checks, otherwise we count an optimization as being performed even if nothing was mutated (ie. it returned early).
2. In cases like `InstCombine`, where we gather optimizations in a pass and then mutate values, we probably would rather skip the gathering pass for performance reasons rather than skip the mutations afterwards.

Highlight MIR as Rust on GitHub

Move capture lowering from THIR to MIR

This allows us to:
- Handle precise Places captured by a closure directly in MIR. Handling
  captures in MIR is easier since we can rely on/ tweak PlaceBuilder to
  generate `mir::Place`s that resemble how we store captures (`hir::Place`).

- Handle `let _ = x` case when feature `capture_disjoint_fields`
  is enabled directly in MIR. This is required to be done in MIR since
  patterns are desugared in MIR.

Closes: rust-lang/project-rfc-2229#25

r? ```@nikomatsakis```

…k-Simulacrum

fix handling the default config for profiler and sanitizers

rust-lang#78354 don't handle the case that user don't add any target-specific config in `[target.*]` of `config.toml`:
```toml
changelog-seen = 2
[llvm]
link-shared = true
[build]
sanitizers = true
profiler = true
[install]
[rust]
[dist]
```

The previes code handle the default config in `Config::prase()`:

```rust
target.sanitizers = cfg.sanitizers.unwrap_or(build.sanitizers.unwrap_or_default());
target.profiler = cfg.profiler.unwrap_or(build.profiler.unwrap_or_default());
config.target_config.insert(TargetSelection::from_user(&triple), target);
```

In this case, `toml.target` don't contain any target, so the above code won't execute. Instead, a default `Target` is insert in https://github.com/rust-lang/rust/blob/c919f490bbcd2b29b74016101f7ec71aaa24bdbb/src/bootstrap/sanity.rs#L162-L166

The default value for `bool` is false, hence the issue in rust-lang#79124

This fix change the type of `sanitizers` and `profiler` to `Option<bool>`, so the default value is `None`, and fallback config is handled in  `Config::sanitizers_enabled` and `Config::profiler_enabled`

fix rust-lang#79124

cc `@Mark-Simulacrum` `@richkadel`

…crum

Allow using `download-ci-llvm` from directories other than the root

Previously, bootstrap.py would attempt to find the LLVM commit from
`src/llvm-project`. However, it assumed it was always being run from the
top-level directory, which isn't always the case.

Before:

```
downloading https://ci-artifacts.rust-lang.org/rustc-builds//rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz

curl: (22) The requested URL returned error: 404
failed to run: curl -# -y 30 -Y 10 --connect-timeout 30 --retry 3 -Sf -o /tmp/tmppyh4w8 https://ci-artifacts.rust-lang.org/rustc-builds//rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
Build completed unsuccessfully in 0:00:02
```

After:

```
downloading https://ci-artifacts.rust-lang.org/rustc-builds/430feb24a46993e5073c1bb1b39da190d83fa2bf/rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
 ###################################################################################################################################################################### 100.0%
extracting /home/joshua/rustc/src/bootstrap/build/cache/llvm-430feb24a46993e5073c1bb1b39da190d83fa2bf-False/rust-dev-nightly-x86_64-unknown-linux-gnu.tar.gz
```

r? ```@Mark-Simulacrum```
cc ```@pnkfelix```

…t-arguments, r=petrochenkov

Permit standalone generic parameters as const generic arguments in macros

Fixes rust-lang#79127.

r? ```@petrochenkov```